Micrometer setting device for boring machines



May 18, 1948. w. F. MITCHELL 2,441,716

MICROMETER SETTING DEVICE FOR BORING MACHINES Original Filed March 18,1943 h I N VEN TOR. gaZlaceffiLZ'i/zefl 1 fi m tingth'e tool bit-of the,boring machine.

Patented May 18, 1948 MICROMETER SETTING DEVICE FOR BORING MACHINESWallace F. Mitchell, Chicago, 11].; assignor to AmmcoTools,-7Inc., acorporation .of Illinois Original application March 18, 1943, Serial No.479,579. Divided and' this application February 17, 1944, Serial No.522,764

7 Claims. 1

My invention relates 'generally'to boring machines adapted'for'theboring of one or a plurality of'so-called in-line bearings and it has todo particularlywith-a' micrometer device for set- This application is adivision of my copending applicatin"Serial No; 479,579, filed'May 18,1943, for

Boringmachine which has matured into Patent No. 2,401,838, grantedJune-11, 1946.

One o'f'the objects :of my invention is to provide an improvedmicrometer device for setting the tool bit of a.boring machine or thelike, whereby the boring operation may be carried out accurately, andwith a higher degree of efliciency than ;possible with machines of likekind heretofore devised.

Another o'bjectis to provide a tool bit With'a means for boring machinesand the like which functions in a purely mechanical manner andeliminates the sense of feel, thereby insuringaccurate setting of thetool bit.

An additional object is to provide a tool bit with a means of theforegoing character which is adapted to be self-retained upon the boring'bar in such a way as to effect a positive micrometer setting of thetool bit. I

Other objects and advantages will become apparent'as this descriptionprogresses and by reference to the drawing wherein- .Figure '1 is a'partial'transverse sectional view of 'a boring machine andillustratingthemanner of use of my micrometer setting'device in settingatool-bitcarried by a boring bar;

Fig; 2 Ban enlarged front elevationalview of the micrometer deviceshown'in'Fig. 1, .the same being illustrated as applied to the boringbarand the tool bit thereof; and

Fig. 3' is a side elevational view partially in vsection of'thestructure shown in Fig. 2.

The "boring machine structure shown in Fig. 1 of 'the drawing isparticularly adapted for the boring-0f crank shaft and cam shaftbearings, and such structure is fullydescribedin mysaid copendingapplication Serial No. 479,579. It isto "beun'derstood that'although myinvention'is particularly suited for the work just stated,'it ma beused'and has utilityinconnection with'the boring of'bearings 'of anykind where similar'conditions-of use are to be-met and wherever themechanism is capable 'of installation for utilization "ofthe'advantages'to be attained throughit.

In the use of "the'foregoing structure for boring crankshaft-bearings,as illustrated-in 1, a cylinder block containing such bearings "isinvertedso as to bring its-crankshaft-pan rail =surfaces H to an-uprightposition for receivingand supporting the 'boring machine. The"crankshaft bearings tOI'bG bored are located within thecylinder'blockat spaced pointsaswill bewell understood. The machine illustratedincludes a boring bar 12 carriedby universally-supported members 43 incentered relation with respect to "the bearings. This mechanism is fullydescribed inim-y said copending application and this is alsotrue ofdrive and feed mechanism for rotating the boring bar 42 and foradvancing it along the bearing being bored.

The boring :operation is effected by a tool -bit 141 carried'by theboring bar 12. More particularly, thetoolbit I4 is adaptedto be mountedin a radial rslideway I5 (Fig. 3) in the boring bar,

the bit being of slightly less dimension than :such slideway to permitfree movement of the same therein. The 'bit 14 is provided with alongitudinalopening 16 which receives and supportsthe endof a springILthe other end of which-spring engages the bottom of the slideway 15 soas to constantly tend/to urge the'bit l 4 outwardly, The

bit 1 4 is adapted'to be secured in position :by 'a set screw l'8, :theadjustment of the bit 14 being determined by-a novelmicrometer device l9.em-

bodying my .invention and which will now bedescribed.

This micrometer device includes a micrometer frame 20 having a bifurcatebar-engaging portion 2 The legs 21 provided'by the bifurcate'barengaging portion 2:1 have V-Shaped bar-engaging flat surfaces orfaces providing peripherally spaced lines 22 of bar contact extendinglongitudinally-of the bar providing a stable and firm engagement betweenthe frame 20 and the-boring 'bar 1'2, E-ach'leg 2 I is also bifurcatedto contact the bar at points spaced longitudinally of the bar, thusdetermining the line 22. The upper part of the micrometer frame '20takes the form of an upstanding finished cylindrical shank 23 whichreceives, and supportsv one end of a micrometer barrel supporting clamp24, the other end of'which receives and supports the micrometer barrel25; The clamp 24 is providedin one endthereof with a'lock screw 26 whichis adapted to engage a pair of spaced-apart depressions in the-uprightor shank 23 so as to lock the clamp 24, together with the micrometerbarrel carried thereby, at the desired operating height along This isprovided for the purpose of increasing the range of the micrometer; Theclamp 24 is further provided'with a clamp screw 21 which, whentightened, securely-locks the'mi- 'crometer barrel '25-'in positiontherein with the spindle oi the micrometer parallel to the shank 23 andperpendicular to the flat surface on the upper arm 2 l In the use ofthis micrometer to set the tool bit M, with a boring bar of a diametersuch that the radius of the bar at the point of contact with the upperarm 2 l coincides with the axis of the spindle of the micrometer, themicrometer is first adjusted to the boring diameter of the bearing to bebored. It is then placed upon the boring bar in the manner illustratedin Fig. 3, being retained firmly in place thereon by a spring clip' 28which is hingedly connected at one end between the legs 2 l of themicrometer support with its other end shaped to snap-engage the boringbar past center in such a way as to self-retain the micrometer inposition upon the boring bar with the flat surfaces of the armstangentially engaging the bar. The micrometer frame is then rotated to aposition, such as illustrated in Fig, 3, wherein the cutting point ofthe boring bit It engages the micrometer spindle anvil 29 on the centerthereof. The micrometer frame and the supporting legs thereof whichengage the boring bar are so located relative to the axis of themicrometer spindle that when the center of the spindle anvil is engagedwith the boring bit a line passing through the axis of the micrometerspindle, the center of the spindle anvil and the point of the boring bitpasses through the line of contact 22 between the upper micrometersupporting leg 2 l and the axis of the boring bar l2. By providing thisarrangement I avoid amplification of error in the micrometer adjustmentwhich may exist due to wear and the like in the tool parts. In the useof the micrometer the properly adjusted micrometer spindle is moved overthe tool bit which at that time is preferably held in a depressedcondition. With the micrometer anvil properly in place the set screw itis loosened sufficiently to permit the spring I! to move the tool bit upinto engagement with the anvil, at which time the set screw is againtightened to securely lock the tool bit in its adjusted condition. Ifdesired, to avoid any possible injury to the tool bit, the micrometerbefore being properly set; but after being positioned on the boring bar,may be turned down to engage the depressed boring bit, the boring bitthen released and the micrometer then set to the proper diameter, afterwhich the tool bit is tightened in place. In either event, after theadjusted tool bit is fastened in place,

the micrometer is detached by releasing thespring clamp 28 sufficientlyto permit the removal from the boring bar.

While it is preferred to use the micrometer device with a boring bar ofsuch diameter that the cutting point of the bit when set engages thespindle anvil 29 on the center thereof, it is obvious that the devicemay be used to accurately set the projection of the bit beyond a bar ofdifferent diameter. Thus, if the boring bar is somewhat smaller indiameter than that above mentioned, the bar will engage the upper orhorizontal arm ZI as viewed in Fig. 3, at a point slightly to the rightof that shown, and the cutting point of the bit when in its uppermostposition will engage the anvil 29 to the right of the center thereof.The micrometer, however, will give a correct reading for the distancethe bit projects beyond the bar, so that, knowing the bar diameter, thebit can be accurately set to bore a given diameter. Similarly, if thebar is somewhat larger in diameter than that above mentioned, the barwill engage the upper or horizontal arm Zi as viewed in Fig. 3, at apoint slightly to the left of that shown, and the cutting point of thebit will engage the anvil 29 to the left of the center thereof.Obviously, the bit setting will also be correct in this instance. Thus,the micrometer device may be used with boring bars of differentdiameters.

Preferably a single boring bit is employed in boring all of thebearings.This is advisable in view of the fact that it would be difficult, inview of the spacing of crank shaft bearings in different engines, toprovide locations which would enable the use of a plurality of boringbits which would simultaneously engage and properly bore all of thebearings at the same time. Therefore, to avoid this difficulty and theinconvenience of trying to align the boring bits with all bearings andto further add to the universaladaptation of the tool, a single bit maybe employed, the same being reapplied and readjusted to the properposition for successively boring the several bearings.

After the boring bit has been adjusted as above explained, the machineis in condition for driving of the boring bar for boring the firstbearing. In the boring operation the boring bar is driven by power meanssuch as an electric drill or other suitable means (not shown).Appropriate feed means is employed for feeding the boring bar along thebearing as it is bored, the same being described in detail in my saidcopending application.

I believe that the construction and operation of my invention will bereadily understood from the foregoing description. The micrometersetting, in accordance with my invention, assures accurate setting ofthe tool bit with resultant accurate boring of the bearing at all timesand under all operating conditions.

I claim:

1. A micrometer device for setting a tool bit having a cutting point andadapted to be mounted in a cylindrical boring bar, which comprises asupport having an upright standard with a forked base portion providingspaced arms rigid with each other and having flat surfaces adapted toseat tangentially on the boring bar at peripherally spaced points, and amicrometer barrel mounted on said standard and adjustably carrying aspindle on an axis extending perpendicularly to the fiat surface on oneof said arms with the end face of said spindle adapted to engage thecutting point ofthe tool bit, said barrel and spindle being calibratedfor determining the extent said cutting point projects beyond the boringbar.

27 A micrometer device for setting a tool bit having a cutting point andadapted to be mounted in a cylindrical boring bar, which comprises asupport having an upright standard With a forked base portion providedwith spaced arms rigid with each other having flat surfaces adapted torest tangentially on the boring bar, a micrometer barrel mounted on'saidstandard and adjustably carrying a spindle on an axis extendingperpendicularly to one of said fiat surfaces with the end faceof saidspindle adapted to engage the cutting point of the tool bit, and meanson said base portion for holding said surface in engage" ment with thebar, said barrel and spindle being calibrated for determining the extentsaid cutting point projects beyond the boring bar.

3. A micrometer device for setting a tool bit having a cutting point andadapted to be mounted in a cylindrical boring bar, which comprises asupport having an upright standard with a forked base portion providedwith spaced arms rigid with each other having flat surfaces extendingperpendicularly to said standard and adapted to rest tangentially onsaid boring bar, a micrometer barrel mounted for adjustment along saidstandard and adjustably carrying a spindle on an axis extendingperpendicularly to said flat surfaces and parallel to said standard, theend face of said spindle being adapted to engage the cutting point ofthe tool bit, and means on said base portion for holding said surface inengagement with the bar, said barrel and spindle being calibrated fordetermining the extent said cutting point projects beyond the boringbar.

4. An instrument for use in setting a tool bit in a boring bar, saidinstrument comprising a V-block having a fiat contact surface on one ofthe legs forming the V adapted to be seated on the cylindrical surfaceof the boring bar for positioning the instrument, and a micrometerhaving a spindle which is micrometrically adjustable lengthwise, saidspindle having an anvil surface at one end which is normalto thelongitudinal axis of the spindle, said micrometer being rigidlysupported by said V-block so that the longitudinal axis of said spindleis perpendicular to the said flat contact surface of the V-block and sorelated to the other leg of the V-blook that said longitudinal axisextended passes through and is perpendicular to the axis of rotation ofthe boring bar, where the boring bar has a certain predetermineddiameter, the aforementioned anvil surface being at the end of thespindle nearest the boring bar.

5. An instrument for use in setting a tool bit in a boring bar, saidinstrument comprising a V-block having a flat contact surface on one ofthe legs forming the V adapted to be seated on the cylindrical surfaceof the boring bar for positioning the instrument, a micrometer having aspindle which is micrometrically adjustable lengthwise, said spindlehaving an anvil surface at one end which is normal to the longitudinalaxis of the spindle, said micrometer being rigidly supported by saidV-block so that the longitudinal axis of said spindle is perpendicularto the said fiat contact surface of the V-block and so related to theother leg "of the V-block that said longitudinal axis extended passesthrough and is perpendicular to the axis of rotation of the boring bar,where the boring bar has a certain predetermined diameter, theaforementioned anvil surface being at the end of the spindle nearest theboring bar, and a spring clip attached to said V- block and. adapted toembrace the boring bar, being thereby effective to secure the instrumentto the boring bar. 7

6. An instrument for use in setting a tool bit in a boring bar, saidinstrument comprising a V-block having a fiat contact surface on one ofthe legs forming the V adapted to be seated on the cylindrical surfaceof the boring bar for positioning the instrument, a shank carried by andprojecting from said V-block, a clamp carried by said shank andadjustably movable lengthwise thereof, and a. micrometer having aspindle which is micrometrically adjustable lengthwise, said spindlehaving an anvil surface at one end which is normal to the longitudinalaxis of the spindle, said micrometer being attached by said clamp tosaid shank and movable with said clamp lengthwise of said shank, thelongitudinal axis of said spindle being parallel to the longitudinalaxis of said shank, said micrometer being so supported that thelongitudinal axis of said spindle is perpendicular to the said fiatcontact surface of the V-block and so related to the other leg of theV-block that the longitudinal axis of the spindle extended passesthrough and is perpendicular to the axis of rotation of the boring bar,where the boring bar has a certain predetermined diameter, theaforementioned anvil surface beingat the end of the spindle nearest theboring bar.

'7. An instrument for use in setting a tool bit in a boring bar, saidinstrument comprising a V-block having flat contact surfaces on the legsforming the V adapted to be seated on the cylindrical surface of theboring bar for positioning the instrument, a shank carried by andprojecting from said V-block, a clamp carried by said shank andadjustably movable lengthwise thereof, a micrometer having a spindlewhich is micrometrically adjust-able lengthwise, said spindle having ananvil surface at one end which is normal to the longitudinal axis of thespindle, said micrometer being attached by said clamp to said shank andmovable with said clamp lengthwise of said shank, the longitudinal axisof said spindle being parallel to the longitudinal axis of said shank,said micrometer being so supported that the longitudinal axis ofsaidspindle is perpendicular to the flat contact surface of one of the legsof the V-block and so related to the other leg of the V-block that thelongitudinal axis of the spindle extended passes through and isperpendicular to the axis of rotation of the boring bar, where theboring bar has a certain predetermined diameter, the aforementionedanvil surface being at the end of the spindle nearest the boring bar,and a clip for securing the instrument to the boring bar, said clipcomprising a leaf spring curved to embrace the boring bar and hingedlyconnected at one end to said V-block.

WALLACE F. MITCHELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 304,389 Willey et al Sept. 2,1884 1,416,810 Foster May 23, 1922 1,421,073 Furness et al June 2'7,1922 1,513,024 Baumann Oct. 28, 1924 1,678,030 Yount July 24, 1928

